Inserter

ABSTRACT

The invention relates to an inserter for an intrauterine system, including a handle ( 3 ) having a longitudinal opening ( 8 ) at its first end, the opening ( 8 ) having a longitudinal axis parallel to the longitudinal axis of the inserter, a first end ( 8   a ) and a second end ( 8   b ), a moveable slider ( 5 ) arranged in the longitudinal opening ( 8 ) and having a first end ( 5   a ) and a second end ( 5   b ), a plunger ( 2 ) attached to the handle ( 3 ), an insertion tube ( 6 ) arranged around the plunger ( 2 ) having a first end and a second end, with its second end attached to the slider ( 5 ). The inserter further includes a lock that reversibly locks locking the intrauterine system in relation to the plunger ( 2 ) via a removal string of the intrauterine system, the lock being controllable by the slider ( 5 ) and/or the insertion tube ( 6 ).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/239,417, filed Apr. 23, 2021, which is a continuation of U.S. patentapplication Ser. No. 15/589,789, filed May 8, 2017 (now U.S. Pat. No.10,987,244), which is a continuation of U.S. patent application Ser. No.13/119,397, filed Mar. 16, 2011 (now U.S. Pat. No. 9,668,912), whichclaims priority to International Patent Application No.PCT/FI2009/050735, filed Sep. 14, 2009, which claims priority to FinnishPatent Application No. 20080523, filed Sep. 17, 2008, the contents ofall of which are incorporated by reference herein.

SUMMARY

The present invention is related to an inserter for positioning anintrauterine device or an intrauterine system in the uterus.

BACKGROUND OF THE INVENTION

Various types of inserters have been developed for the positioning ofmechanical and copper wire-containing intrauterine devices (IUDs) aswell as of intrauterine systems having a drug containing cylinder(IUSs). In the following, IUD and IUS can be used interchangeably andwhen one is mentioned, it is to be understood that either of them can beused. Simple rod-shaped inserters have been suggested for insertingrelatively small or sufficiently flexible intrauterine devices in theiroriginal, expanded shape by using simple push-in technique. However,most common inserters are constructed for introducing the device intothe uterus in a contracted state. These inserters usually comprise aninsertion tube having a relatively narrow diameter and a rounded, bluntend which will pass through the cervical canal easily and will notdamage or injure the fundus upon contact therewith, and a plunger insidethe insertion tube. Prior to insertion the device, whether an IUD or anIUS, is usually retracted into the insertion tube either by means ofstring(s) attached to the device and intended for the removal of thedevice from the uterus, or by pushing the device into the insertion tubeby a plunger with inserters having a special window to adapt the devicein the expanded shape (see for example GB 1 403 393). Then the insertiontube with the device therein is introduced through the cervical canalinto the uterus. When the device is correctly positioned, it is releasedeither by pushing the plunger towards the uterus or by holding theplunger steady and by retracting the insertion tube outwards. Onceexpulsed from the insertion tube within the uterine cavity, the deviceis supposed to resume its original expanded shape.

A typical example of an intrauterine device has a T-shaped bodyfabricated of plastic material and consisting of an elongated body parthaving at one end a transverse member comprising two wings, the elongatemember and the transverse member forming a substantially T-shaped piecewhen the device is in the expanded configuration, for example positionedin the uterus. The tips of these wings are preferably hemispherical inorder to facilitate the introduction of the device through the cervicalcanal. The elongate member has a copper spiral or wire or a hormonecapsule arranged around the body. The end of the vertical body part hasa loop with a string or strings attached to it, with which the devicecan be removed from the uterus after use or whenever needed.

The diameter of the elongate member in intrauterine systems having adrug containing cylinder is greater than in copper wire-containing IUDsor mechanical devices, and thus the diameter of the insertion tube alsohas to be larger. However, the frames of these intrauterine systems, orin the commonly used T-shaped systems the hemispherical ends of thetransverse member, are small in relation to the diameter of theinsertion tube. Therefore the correct positioning of the IUS within theinsertion tube is extremely important, and this will only be attained byproperly handling the removal string(s) during the preparatory steps andinsertion as well as when finally releasing the IUS after insertion.Challenging steps, which will be exemplified with a common T-shapeddevice, apply as well to intrauterine systems having another type offrame, for example 7-shaped or closed, continuous frames.

For the insertion of a T-shaped intrauterine system it is extremelyimportant that the hemispherical ends of the transverse member are inthe exactly correct position in relation to the edge of the insertiontube at the moment of introducing the device in the uterus. If the IUSis pulled into the insertion tube by means of the removal string, whichis usually the case with the existing devices, it is understandable thatit is difficult to make the IUS stop in the correct position, especiallyif the relative movement of the insertion tube and the plunger is notrestricted by any stop member. Pulling with too much force easily makesthese ends enter almost completely into the insertion tube. During theinsertion of the device, the sharp edges of the insertion tube mayinterfere with the introduction of the device through the cervicalcanal. On the other hand, if the device is not drawn deep enough intothe insertion tube, the frame ends project outwardly because of arelatively wide insertion tube. The diameter at the level of the wingsremains too wide, which makes the introduction of the device moredifficult. It is easier to make the wings stop in the correct positionin the case of copper-wire devices, because then the insertion tube isnarrow in relation to the wings and therefore there is no risk of thewings being drawn too deep into the tube even by forceful pulling.

When the device is pulled into the insertion tube, it is important thatthe device is directed onto the plunger in the correct position, i.e.without damaging the loop, the rest of the body or the string(s). If thedevice is pulled onto the plunger in a wrong position, the edges of theinsertion tube or the plunger can damage the loop or the body. Ifpulling is continued and the device does not turn into the correctposition, the string(s) will finally cut through the loop or the body,which can also cause the device to get jammed within the insertion tubeor plunger.

The European patent application EP 1 691 740 relates to an inserter,with which the correct positioning and directional stiffness of thedevice in the inserter prior to and during insertion can be ensured, forinstance, by shaping the forward end of the plunger such that the IUSassumes a specified constant configuration when drawn into the insertiontube. The IUS will thus not be twisted during insertion.

European patent EP 798 999 relates to an inserter, which allows thecorrect positioning of an IUS also in those cases in which the elongatemember of a T-shaped device contains active material, which involves adiameter larger than that of an elongate member of a copper-wire IUD.The inserter comprises a plunger, a handle attached to the plunger, astring for the removal of the IUS, a cleft on the end of the handle tolock the string(s) in such a way that the IUS remains immobile inrelation to the plunger, and an insertion tube around the plunger. TheIUS is drawn into the insertion tube by pushing the tube over the deviceor by pulling on the removal threads whereafter the threads are manuallylocked in the cleft. The relative movement of the plunger and theprotective tube is restricted by a stop member or stop members toascertain that the correct configuration of the IUS is achieved. Thestop members ensure that the front edge of the insertion tube is stoppedin a configuration in which the hemispherical tips of the T-wings remainpartly uncovered by the insertion tube but the wings nevertheless remainpressed against each other. This inserter overcomes many of the problemsencountered with the conventional inserters, but the string(s) stillneed to be manually handled and locked.

OBJECT AND SUMMARY OF THE INVENTION

An object of the invention is to provide a simple, easy to use inserterfor the positioning of an intrauterine system in the uterus by solvingat least partially at least some of the problems mentioned above. Anobject of the invention is particularly to provide an inserter having animproved system for locking and releasing the removal strings of an IUSin the necessary steps during the insertion process so that no manualhandling of the strings as such is needed.

A typical inserter for an intrauterine system according to the presentinvention, comprises

-   -   a handle having a longitudinal opening at its first end, said        opening having a longitudinal axis parallel to the longitudinal        axis of the inserter, a first end and a second end,    -   a movable slider arranged in said longitudinal opening and        having a first end and a second end,    -   a plunger attached to the handle,    -   an insertion tube arranged around the plunger having a first end        and a second end, with its second end attached to the slider.

The inserter is characterized in that it further comprises locking meansfor reversibly locking the intrauterine system in relation to theplunger via a removal string of the intrauterine system, said lockingmeans being controllable by the slider and/or the insertion tube.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a general overview of an inserter according to anembodiment of the invention.

FIGS. 2A, 2B and 2C illustrate an operating principle of an inserteraccording to an embodiment of the invention.

FIGS. 3A, 3B and 3C illustrate an operating principle of the insertershown in FIGS. 2A, 2B and 2C for insertion of another type ofintrauterine system.

FIGS. 4A, 4B, 4C and 4D illustrate a correct positioning of an IUS in aninsertion tube of an inserter according to the present invention.

FIGS. 5A and 5B illustrate a locking means according to an embodiment ofthe invention.

FIGS. 6A and 6B illustrate a locking means according to anotherembodiment of the invention.

FIGS. 7A and 7B illustrate a locking means according to yet anotherembodiment of the invention.

FIGS. 8A and 8B illustrate a locking means according to a furtherembodiment of the invention.

FIGS. 9A and 9B illustrate a locking means according to yet anotherembodiment of the invention.

FIG. 10 illustrates a cross-section of an inserter according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A typical inserter for an intrauterine system according to the presentinvention, comprises

-   -   a handle having a longitudinal opening at its first end, said        opening having a longitudinal axis parallel to the longitudinal        axis of the inserter, a first end and a 10 second end,    -   a movable slider arranged in said longitudinal opening and        having a first end and a second end,    -   a plunger attached to the handle,    -   an insertion tube arranged around the plunger having a first end        and a second end, with its second end attached to the slider        and/or the insertion tube.

The inserter is characterized in that it further comprises locking meansfor reversibly locking the intrauterine system in relation to theplunger via a removal string of the intrauterine system, said lockingmeans being controllable by the slider and/or the insertion tube. Thismeans that the locking means can also be controlled by a part of theslider and/or of the insertion tube, such as an extension of either orboth of them.

The inserter according to the present invention thus comprises means forreversibly locking the intrauterine system, for example by locking theremoval string or strings of the intrauterine system, in such a way thatthe device remains immobile in relation to the plunger during thenecessary steps prior to insertion and during insertion but can bereleased after the IUS has correctly been positioned in the uterus.Moreover, with the present invention, no manual handling of the stringsas such is needed, which increases security and hygiene.

The longitudinal opening on the handle can have be also quite narrow anddoes not need to be symmetrically positioned on the handle and withrespect to the longitudinal axis.

The invention therefore provides an easy to use inserter, by which onlyfew simple steps are needed to prepare for the insertion and to securelyinstall and position an intrauterine system into the uterus.

In the present description and claims, by first ends are typically meantthe ends that are closer to the uterus during the insertion of theintrauterine system. Second ends are the ends opposite to the firstends. Moreover, the terms IUS or IUD are used when describing thepreferred embodiment of the present invention, but these are not to beconstrued as limiting the claims. The term removal string means one ormore strings used for removing the system once it reaches the end of itsuse time. There may thus be one or more such strings, and this termencompasses also strings that are not used for removal but only forlocking the device during insertion.

According to one embodiment of the invention, the inserter comprisesstop members to control the movement of the slider.

According to a preferable embodiment of the invention, the first end ofthe opening and the first end of the slider form a first pair of stopmembers, and the second end of the opening and the second end of theslider form a second pair of stop members.

A part of the handle thus comprises an opening having a first end and asecond end and running in the longitudinal direction of the plunger. Thehandle also has at its first end a channel in which the insertion tubecan slide in the longitudinal direction. At the second end, i.e. distalend (away from the uterus) the insertion tube is attached to the slideror to a means which can be used to move the slider and preferably formsat least a part of the slider. With respect to the startingconfiguration, the front surface of said means and the surface at thefirst end of the opening (the end directed towards the IUS) togetherform the first pair of stop members. By simply pushing the slider or themeans for moving the slider forwards in the opening the sliderarrangement and the insertion tube attached to it can be moved inrelation to the plunger to push the insertion tube past the plunger atdistance, which corresponds substantially to the length of the IUSassembled for insertion. Because the string(s) and the IUS remainimmobile all the time, the IUS is retracted in the insertion tube. Torelease the IUS after it has been positioned in the uterus the sliderand the insertion tube will be pulled backwards past the plunger thedistance determined by the second pair of stop members, formed by therear surface of the means to move the slider and the surface at thesecond end of the opening.

The handle can have many shapes and is preferably designed for easyhandling of the inserter even by using only one hand. The plungerattached to the handle is advantageously hollow or has a groove or borerunning in the axial direction thus allowing the string(s) to slidefreely in it, without any risk of them getting jammed between theplunger and the insertion tube. The first end, i.e. the forward end ofthe plunger is preferably suitably shaped to have for example a notch,an indentation, an eyelet, a funnel or a groove to adapt to the lowerend of the intrauterine system and to enable the optimal and securepositioning of the intrauterine system on the plunger so that theprobability of damage to the intrauterine system is minimal. Thus theIUS will not be twisted when it is drawn in the insertion tube or duringinsertion and assumes a specified constant configuration when released.

The forward parts (parts directed towards the uterus) of the plunger andthe insertion tube can be straight or curved so as to conform to theanatomy of the uterus. Preferably these parts are made from a flexiblematerial in order to avoid perforation of the uterus.

The slider mechanism is preferably inside the handle and comprises atleast one elongated element, which can be moved in the longitudinaldirection of the plunger. According to an embodiment of the inventionthe slider comprises means to move the slider, which preferably is apart of the slider, and the insertion tube attached to said means.According to another embodiment of the invention the slider comprises atleast two elements, preferably parallel, which are combined on at leastone point by a transversal member. The transversal member may formmeans, for example a knob or switch, by which the slider can be moved.The handle can comprise one or more means to connect the slider elementsand to facilitate the movement of the slider, for example a support, ashoulder, a holder, a saddle, a groove or a slot. The slider preferablycomprises at least one structural element, for example an extension,which is capable to generate the necessary operation of the lockingmeans to keep the strings immobilized during storage or duringpreparatory steps before insertion or during insertion and/or to releasethe string(s) when the slider is moved to the backward position.

The locking means is a lock which, induced by the movement of the slideror of the means to move the slider and the insertion tube, canimmobilise the removal string(s) to hold the IUS in a stable positionand/or to release the string(s) after insertion to release the IUS.Particularly, the invention relates to a locking means which comprisesan object capable of reversibly preventing and/or allowing the movementof the string(s) by at least partly moving or pivoting from the originalposition, for example rotating around a shaft or an axle, and verticallyor horizontally attached to the handle. The object may have severalshapes and may be for example round or rod-shaped, wedge, polygonal orrectangular with rounded or sharp corners. The surface of the objectpreferably comprises one or more extensions having variable size andshape, for example a knob, a rib or a switch. When the slider mechanismis moving backwards, at a suitable point a part or an extension of theslider or of the insertion tube is pressed against at least oneextension of the object thus changing its orientation enough relative tothe original position to cause release of the string(s). Preferably theobject has a slot or pinhole through which the string(s) run. Thelocking means may also comprise at least one counterpart against whichthe string(s) are pressed by the object and thus reversibly immobilizedin the locking position. The counterpart has a suitable shape adapted tofit at least some part of the surface of the object. An extension, orextensions of the object can be used to keep the object and thecounterpart in a fixed configuration until the slider is moved backwardsto release the IUS. The counterpart preferably has a suitable design tokeep the string(s) in proper direction, for example a slot or pinholethrough which the string(s) run. Further, the object and said at leastone counterpart have preferably a suitable length and diameter to fitinside the handle.

According to one embodiment of the invention, the locking means thuscomprises

-   -   a main part,    -   a first extension of the main part having an abutment surface,    -   a counterpart adapted to form a blocking together with the main        part,        wherein the locking means is rotatably mounted on the inserter.

According to another embodiment of the invention the main part comprisesan opening or a slot in a diagonal direction through essentially thewhole diameter of the main part, adapted to receive at least one removalstring of the intrauterine system.

According to yet another embodiment of the invention, the locking meanscomprises

-   -   a main part,    -   a first extension of the main part having an abutment surface,    -   a second extension of the main part having a wedge-like shape,    -   a counterpart,        wherein the second extension is adapted to form a blocking        together with the counterpart and the locking means is rotatably        mounted on the inserter.

The locking means can be for example mounted on the handle of theinserter. According to one embodiment of the invention, the main parthas essentially the shape of a cylinder, or it is of triangular shape,or of any other suitable shape.

According to one embodiment of the invention the slider comprises anextension adapted to abut on the abutment surface of the first extensionof the main part of the locking means.

According to one other embodiment of the invention the locking meanscomprises a main part comprising a first extension and a secondextension arranged, in their initial position, to be essentially incontact with each other to from a blocking, and wherein the slider, apart of the slider, the insertion tube or a part of the insertion tubeis arranged to protrude into the main part of the locking means so as toseparate the first and second extensions from each other.

According to yet one other embodiment of the invention the locking meanscomprises

-   -   a first locking part and a second locking part movably mounted        on the inserter and arranged, in their initial position, to be        essentially in contact with each other to form a blocking, and    -   a first protrusion and a second protrusion arranged on a        location selected from the group consisting of the inner surface        of the insertion tube, the outer surface of the insertion tube,        the inner surface of the slider and the outer surface of the        slider,        wherein the first and second protrusions are arranged so as to        move the first and second locking parts to a second position        when moving the insertion tube.

The locking means could also be welding, gluing, cutting, knot oradhesion. The strings could thus be for example attached to the body ofthe inserter by welding (for example by heating), gluing with glue orattaching with an adhesive agent (such as sticker). The slider wouldthen release the attachment when moving to release the device. Otheroptions could be a knot or other mechanical hindrance, when the slotprovided for the strings is larger in the releasing position. The slidercould also comprise a blade that cuts the strings loose from theinserter.

It is obvious to a person skilled in the art that, in accordance withthe above description, the locking means can be of any other kind thanthose specifically listed above as well as a combination of any of theembodiments and features described above.

According to another embodiment of the invention, the inserter furthercomprises a flange arranged on the insertion tube. This flange can beadjusted to correspond to the depth of the uterus in order to correctlyposition the device during its insertion.

The inserter according to the invention is suitable for the positioningof intrauterine devices and intrauterine systems having different sizesand shapes as long as these can be managed to enter the insertion tubeby appropriate arrangements.

During the preparatory steps the string(s) are locked but they arereleased automatically by the slider, when it is drawn backwards inorder to release the IUS. Compared to previous inserters, there is noneed to manually handle the removal strings during the preparatory stepsand during insertion, which eliminates the possibility of user-mademistakes.

The invention further relates to a kit comprising an intrauterine systemand an inserter according to the present invention. The intrauterinesystem can be any device known in the art. Any details and embodimentslisted above naturally apply mutatis mutandis to the kit according tothe invention.

The present invention also relates to a method for positioning aintrauterine system in a uterus of a patient, wherein the method uses aninserter according to the present invention. The method comprises thesteps of

-   -   moving the slider towards the first end of the opening until the        first end of the opening is in contact with the first end of the        slider, and the intrauterine system is substantially inside the        insertion tube,    -   introducing the inserter into the uterus of the patient until        the intrauterine system is in its correct location,    -   moving the slider towards the second end of the opening until        the second end of the opening is in contact with the second end        of the slider, thus releasing the intrauterine system from the        inserter,    -   removing the inserter from the uterus of the patient.

The method advantageously contains, at its beginning, the further stepsof sounding the uterus using a probe, and setting the flange accordinglyto show the correct insertion depth.

An example of the method for positioning the intrauterine system isgiven hereafter. To insert the IUS only few steps are needed. To preparefor the insertion the sterile package is carefully opened. The IUS is ina correct configuration relative to the inserter and there is no need toalign the device or for example to rearrange or correct the horizontalarms of a T or a 7-shaped device. The IUS is positioned at the forwardend of the plunger in the expanded configuration and with the lower endof the device abutting the end of the plunger. In case of intrauterinesystems having for example the shape of T or 7, the elongate member andthe hormone cylinder are preferably protected by the insertion tube andthe wing(s) of the transverse member remain outside the insertion tubein expanded configuration in order to prevent fatigue. The removalstring(s) attached to the device, running in the groove of the plungerand ending at the end of the handle, are immobilised by the lockingmeans to keep the IUS at a steady and correct position until it isreleased in the uterus.

Then, the handle is held tightly and the insertion tube is moved towardsthe IUS by pushing the slider forwards until the first pair of stopmembers gets together, thereby stopping the movement of the insertiontube. At this moment the IUS is substantially inside the insertion tube,and ready for insertion. The distance the slider can be moved forwardsfrom the preliminary position substantially corresponds to the length ofthe IUS assembled for insertion. This ensures that the front edge of theinsertion tube, the edge toward the uterus, is stopped in aconfiguration in which upper ends of the intrauterine system or thehemispherical tips of the wings remain partly uncovered by the insertiontube, but nevertheless remain pressed against each other.

The inserter is introduced into the uterus until the IUS is in thecorrect location, which is determined beforehand by using a probe. Torelease the IUS the insertion tube is drawn backwards by retracting theslider towards the handle all the way until the second pair of stopmembers gets together. The movement of the slider also releases thelocking means thus releasing the removal string(s). The distance theslider or the insertion tube moves has been selected so that at thispoint the IUS has completely been released from the insertion tube.

The inserter thus allows easy and secure positioning of an IUS. The useof the slider mechanism is straightforward and the locking means to holdthe string(s) and the IUS immobile long enough as well as thepredetermined distance the insertion tube can be moved in each stepguarantee an accurate positioning of the IUS during insertion and itsaccurate release. The stop members and the designed frontal end of theplunger control the correct positioning of the IUS in the insertiontube. Hence it is not necessary to provide so much clearing between theplunger and the insertion tube as in conventional inserters in which theIUS is positioned by retraction without any stop member. This results inan extremely stable construction, which involves no risk of irremediablebending of the tube.

DETAILED DESCRIPTION OF THE DRAWING

In the following description, the term slider and the correspondingreference number are used to designate both the slider itself and themeans to move the slider attached to the slider. The term slider is thusused for convenience of reading.

FIG. 1 illustrates a general overview of an inserter according to theinvention. The inserter comprises a handle 3, a plunger 2 attached tothe handle, a slider 5, an insertion tube 6 around the plunger, thesecond end of the insertion tube being attached to the slider or to themeans to move the slider. The inserter also comprises means forreversibly locking the string(s) (not shown) in such a way that the IUSremains immobile in relation to the plunger during the necessary stepsprior to and during insertion, and again for releasing the string(s) andthe IUS after it has been inserted. The inserter further comprises anopening 8 in a part of the handle, a channel 9 in which the insertiontube slides in the longitudinal direction, and a flange 4, which can beadjusted so that its distance from the first end of the insertion tubecorresponds to the depth of the uterus.

The part of the handle 3 that is closer to its first end has an opening8 having a first end 8 a and a second end 8 b, which opening runs in thedirection of the plunger 2. The surface of the first end 5 a of theslider 5 and the surface at the first end 8 a of the opening 8 togetherform a first pair of stop members, and the surface of the second end 5 bof the slider 5 and the surface at the second end 8 b of the opening 8together form a second pair of stop members. When inserting the IUS, theslider and the insertion tube can be moved forward until the surfaces 8a and 5 a contact each other, and backwards until the surfaces 5 b and 8b contact each other. The locking means are arranged inside the handle 3and are thus not visible.

FIGS. 2A, 2B and 2C illustrate an operating principle of an inserteraccording to an embodiment of the invention.

FIG. 2A shows an inserter and a T-shaped IUS 1 in a configuration asthey are in a sterilized package. The IUS is placed in the first end(i.e. the front end, i.e. the end of entry into the uterus) of theinserter so that the elongate member of the device with a drugcontaining reservoir is inside the insertion tube 6 with the tip of theelongate member abutting the end of the plunger (shown with referencenumber 2 a). The means to move the slider 5 is on the starting orinitial position, and the removal string(s) inside the inserter aretightened and locked by the locking means (not shown in the Figure).

FIG. 2B illustrates the first step of insertion procedure. While holdingthe handle 3, the insertion tube is moved towards the IUS by pushing theslider forward until surface 5 a abuts the surface 8 a of the opening 8of the handle 3, thereby stopping the movement of the insertion tube. Atthis moment the IUS is substantially inside the insertion tube, andready for insertion. The distance the slider and the insertion tube willmove between the surfaces 5 a and 8 a has been designed substantially tocorrespond to the length of the IUS assembled for insertion. The firstend of the insertion tube is stopped at a level at which thehemispherical tips (10 a, 10 b as shown in FIGS. 4A and 4B) of the wingsof the IUS partly remain uncovered by the insertion tube, while thewings still remain together.

FIG. 2C illustrates the procedure to release the IUS. The device in theconfiguration according to FIG. 2B is introduced into the uterus untilthe IUS is in the correct location, where after the device is releasedfrom the insertion tube. While retaining the inserter stationary, theinsertion tube is retracted towards the handle by moving the slider 5backwards until the surface 5 b of the slider abuts the surface 8 b ofthe opening 8 of the handle 3. The distance the slider and the insertiontube can be moved has been selected to indicate clearly the moment atwhich the IUS has completely been released from the insertion tubemoving towards the handle.

FIGS. 3A, 3B and 3C illustrate an operating principle of the insertershown in FIGS. 2A, 2B and 2C for insertion of another type ofintrauterine system. For this intrauterine system, the triangular frameof the IUS can be bent such that the frame is two-fold on its wholelength when ready for insertion, or such that it is four-fold on the tophalf of its length.

FIGS. 4A, 4B, 4C and 4D illustrate a correct positioning of an IUS in aninsertion tube of an inserter according to the present invention. FIG.4A shows one type of IUS 1 and FIG. 4B its position in an insertiontube: the first end of the insertion tube 6 is stopped at a level atwhich the hemispherical tips 10 a, 10 b of the wings of a T-shaped IUSpartly remain uncovered by the protective tube 6. FIG. 4C presentsanother type of IUS 1, having a frame with triangular shape. In FIG. 4Dis shown how the outer end 10 c of the retracted and compressed closedframe partly remain uncovered by the protective tube 6.

FIGS. 5A and 5B illustrate a locking means according to an embodiment ofthe invention. The locking means are arranged preferably inside of thehandle 3, on any of the inside surfaces of the handle. The locking meansare used to immobilise and release the string(s) of the IUS.

FIG. 5A illustrates a locking means according to an embodiment of theinvention comprising a main part 11 having essentially the shape of acylinder and comprising an opening 12 there through in a diagonaldirection. The string(s) 7 of the IUS pass through the opening 12. Themain part 11 is rotatably mounted on the handle, on a shaft or an axle(not shown). The locking means also comprises a counterpart 13, suchthat in the locking position the string(s) are immobilized between thecounterpart and the main part. The counterpart thus has a suitable shapeadapted to fit to a part of the surface of the main part. When theslider is moving backwards, at a suitable point a part or an extensionof the slider is pressed against the extension 11 a of the main part 11thus turning it enough to release the string(s), as shown in FIG. 5B.

FIGS. 6A and 6B illustrate a locking means according to anotherembodiment of the invention. FIG. 6A illustrates an object similar tothe one presented in FIG. 5A, but having a different construction of theextension 11 a.

FIGS. 7A and 7B illustrate a locking means according to yet anotherembodiment of the invention. This is a side view of a locking meanshaving a cylindrically shaped main part 14 which comprises twoextensions 14 a and 14 b. The main part 14 can rotate around a shaft oran axle 16 and is preferably attached to a shorter side of the innersurface of the handle. The locking means also comprises a counterpart 15such that the string(s) 4 are immobilised between the counterpart 15 andthe extension 14 b. The counterpart 15 has a suitable shape adapted tofit to a part of the surface of the extension 14 b. When the slider ismoving backwards, at a suitable point a part or an extension of theslider is pressed against the extension 14 a thus turning it enough torelease the string(s), as shown in FIG. 7B. In this case the handle canalso comprise a groove in which the string(s) run (not shown).

FIGS. 8A and 8B illustrate a locking means according to a furtherembodiment of the invention. The locking means 17 comprises twoextensions 17 a and 17 b to immobilize the strings as shown in FIG. 8A.When the slider 5 and the insertion tube 6 move backwards the sliderprotrudes into the locking means at least partly to expand the meansenough to separate the extensions 17 a and 17 b and to release thestrings, as shown in FIG. 8B.

FIGS. 9A and 9B illustrate a locking means according to a yet anotherembodiment of the invention. The locking means comprises two parts 18 aand 18 b to immobilize the strings as shown in FIG. 9A, said parts beingable to move or turn from their original position. The slider 5 has twoextensions 19 a and 19 b. When the slider 5 and the insertion tube 6move backwards the slider extensions turn the locking parts 18 a and 18b apart from each other, enough to release the strings, as shown in FIG.9B.

FIG. 10 shows a cross-section of an inserter and a T-shaped intrauterinesystem 1. The intrauterine system 1 includes a reservoir 1 a containinga hormone. A dashed circle indicates an area inside the handle 3 wherethe lock is arranged. The lock is arranged inside the handle 3 andadapted to reversibly lock the intrauterine system 1 in relation to theplunger 2. The main part 11 is mounted on a shaft or axle on the handle3.

The invention claimed is:
 1. A kit comprising: an intrauterine systemcomprising: a reservoir containing a hormone; and a removal stringattached to the intrauterine system; and an inserter comprising: ahandle comprising: a longitudinal opening; and a slider arranged in thelongitudinal opening; a plunger attached to the handle; an insertiontube attached to the slider; and a lock arranged inside the handle andadapted to reversibly lock the intrauterine system in relation to theplunger via the removal string, the lock being controllable by theslider, the lock comprising: a main part that is rotatably mounted on ashaft or an axle on the handle, an extension, and a counterpart, whereinthe removal string is immobilized between the main part and thecounterpart when the lock is in a locked position, and wherein theremoval string is released when a part of the slider presses against theextension to turn the main part around the shaft or the axle.
 2. The kitof claim 1, wherein the hormone is levonorgestrel.
 3. The kit of claim1, wherein the reservoir further comprises an elastomer.
 4. The kit ofclaim 3, wherein the elastomer is poly(dimethylsiloxane).
 5. The kit ofclaim 1, wherein moving the slider forward causes the lock to move intothe locked position.
 6. The kit of claim 1, wherein moving the sliderbackwards causes the lock to move into a released position.
 7. The kitof claim 1, further comprising a flange arranged on the insertion tubethat is adjustable such that its distance from a front end of theintrauterine system corresponds to a depth of a uterus.
 8. The kit ofclaim 1, wherein the handle forms a channel in which the insertion tubeslides in a longitudinal direction.
 9. The kit of claim 1, wherein themain part comprises an opening through which the removal string passes.10. The kit of claim 1, wherein the shaft or the axle is irregularlyshaped.
 11. A method for positioning an intrauterine system within auterus, the method comprising: (a) providing an intrauterine systemhaving a reservoir containing a hormone and a removal string attached tothe intrauterine system; (b) sounding the uterus to determine a depthfor placement of the intrauterine system; (c) holding an inserter in onehand, the inserter comprising: a handle comprising: a longitudinalopening, the longitudinal opening having a first end and a second end;and a slider arranged in the longitudinal opening, the slider beingmovable and having a first end and a second end; a plunger attached tothe handle; an insertion tube attached to the slider; and a lockarranged inside the handle and adapted to reversibly lock theintrauterine system in relation to the plunger via the removal string,the lock being controllable by the slider, the lock comprising: a mainpart that is rotatably mounted on a shaft or an axle on the handle, anextension, and a counterpart, wherein the removal string is immobilizedbetween the main part and the counterpart when the lock is in a lockedposition, and wherein the removal string is released when a part of theslider presses against the extension to turn the main part around theshaft or the axle; (d) introducing the inserter into the uterus with theone hand until the intrauterine system is at the depth determined instep (b); and (e) moving the slider with one digit of the one hand,thereby releasing the removal string and intrauterine system within theuterus.
 12. The method of claim 11, wherein the hormone islevonorgestrel.
 13. A method of providing contraception in a patient,comprising: (a) providing an intrauterine system having a reservoircomprising a hormone and a removal string attached to the intrauterinesystem; (b) sounding a uterus to predetermine a depth for placement ofthe intrauterine system; (c) holding an inserter in one hand, theinserter comprising: a handle comprising: a longitudinal opening, thelongitudinal opening having a first end and a second end; and a sliderarranged in the longitudinal opening, the slider being movable andhaving a first end and a second end; a plunger attached to the handle;an insertion tube attached to the slider; and a lock arranged inside thehandle and adapted to reversibly lock the intrauterine system inrelation to the plunger via the removal string, the lock beingcontrollable by the slider, the lock comprising: a main part that isrotatably mounted on a shaft or an axle on the handle, an extension, anda counterpart, wherein the removal string is immobilized between themain part and the counterpart when the lock is in a locked position, andwherein the removal string is released when a part of the slider pressesagainst the extension to turn the main part around the shaft or theaxle; (d) introducing the inserter into the uterus with the one handuntil the intrauterine system is at the depth predetermined in step (b);and (e) moving the slider with one digit of the one hand, therebyreleasing the removal string and intrauterine system within the uterus.14. The method of claim 13, wherein the hormone is levonorgestrel.
 15. Amethod of preventing pregnancy in a patient, comprising: (a) providingan intrauterine system having a reservoir comprising a hormone and aremoval string attached to the intrauterine system; (b) sounding auterus to predetermine a depth for placement of the intrauterine system;(c) holding an inserter in one hand, the inserter comprising: a handlecomprising: a longitudinal opening, the longitudinal opening having afirst end and a second end; and a slider arranged in the longitudinalopening, the slider being movable and having a first end and a secondend; a plunger attached to the handle; an insertion tube attached to theslider; and a lock arranged inside the handle and adapted to reversiblylock the intrauterine system in relation to the plunger via the removalstring, the lock being controllable by the slider, the lock comprising:a main part that is rotatably mounted on a shaft or an axle on thehandle, an extension, and a counterpart, wherein the removal string isimmobilized between the main part and the counterpart when the lock isin a locked position, and wherein the removal string is released when apart of the slider presses against the extension to turn the main partaround the shaft or the axle; (d) introducing the inserter into theuterus with the one hand until the intrauterine system is at the depthpredetermined in step (b); and (e) moving the slider with one digit ofthe one hand, thereby releasing the removal string and intrauterinesystem within the uterus.
 16. The method of claim 15, wherein thehormone is levonorgestrel.